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GENETIC STRUCTURE OF CREEK CHUB (SEMOTILUS ATROMACULATUS) POPULATIONS IN COAL MINING-IMPACTED AREAS OF THE EASTERN UNITED STATES, AS DETERMINED BY MTDNA SEQUENCING AND AFLP ANALYSIS
Citation:
Christ, S A., M J. Bagley, E R. Waits, AND G P. Toth. GENETIC STRUCTURE OF CREEK CHUB (SEMOTILUS ATROMACULATUS) POPULATIONS IN COAL MINING-IMPACTED AREAS OF THE EASTERN UNITED STATES, AS DETERMINED BY MTDNA SEQUENCING AND AFLP ANALYSIS. Presented at American Society of Ichthyologists and Herpetologists, Kansas City, MO, July 3-8, 2002.
Impact/Purpose:
The objective of this task is to develop molecular indicators to evaluate the integrity and sustainability of aquatic fish, invertebrate, and plant communities (GPRA goal 4.5.2). Specifically, this subtask aims to evaluate methods for the measurement of:
fish and invertebrate community composition, especially for morphologically indistinct (cryptic) species
population genetic structure of aquatic indicator species and its relationship to landscape determinants of population structure (to aid in defining natural assessment units and to allow correlation of population substructure with regional stressor coverages)
genetic diversity within populations of aquatic indicator species, as an indicator of vulnerability to further exposure and as an indicator of cumulative exposure
patterns of temporal change in genetic diversity of aquatic indicator species, as a monitoring tool for establishing long-term population trends.
Description:
Analysis of intraspecific patterns in genetic diversity of stream fishes provides a potentially powerful method for assessing the status and trends in the condition of aquatic ecosystems. We analyzed mitochondrial DNA (mtDNA) sequences (590 bases of cytochrome B) and nuclear DNA patterns (109 amplified fragment length polymorphisms; AFLP) of creek chub (Semotilus atromaculatus) populations from ten sites located in coal mining regions of Pennsylvania and West Virginia. The ten sites differed dramatically in measured conductivity (range: 153-3590 uS), but less so in pH (range: 6.61-8.31), total dissolved aluminum (range: 5-184 ug/L), and in a measure of invertebrate diversity (Hilsenhoff Biotic Index, range: 3.9-5.7). Sequence analysis of 164 individuals revealed 27 Cytochrome B haplotypes, that were highly structured by geographic locale. An analysis of molecular variance (AMOVA) indicated that 61% of haplotypic variation could be attributed to differences in DNA sequence among sites. Similar analysis of AFLP polymorphisms among 174 individuals indicated that 11% of nuclear DNA variation was due to differences among sites. Despite large genetic differences among populations, overall genetic diversity within populations did not differ significantly. Thus, no evidence was found for a strong link between genetic diversity within populations and several measures of environmental quality.